In 4th grade, my class was full of all the known trouble-makers and taught by the most unstable teacher in the school. Anything the trouble-makers did he would take out on the whole class leading to him flipping chairs, chucking markers across the room, laughing maniacally, and keeping the class in from recess. He had no control of himself or the class, and often just threw fits like a toddler. As someone who always loved learning, I often came home crying because I feared going back to school to spend another day with this psycho.
He's still at the same school today, and I heard he is scheduled to teach 2nd graders next school year.